C///

\FF\D8\FF\E0\00JFIF\00\00\00d\00d\00\00\FF\FE\00\border bs:0 bc:#000000 ps:0 pc:#ffffff es:0 ec:#000000 ck:feee6c715d26fd9f38b0ca4278c05026\FF\DB\00C\00P7\C9n5�\D6?\BD�\9Ds\EBp\9F[`8m\B7)o\B5\E8\E6I\99\FE3]]A2\BA\8Cw\D6E\93\\DEv\C8\009\F2\F1NI?uc\\F5\EA\96k\xN<~buv\EA\C8\D7 \8B\84\CEcxI\BBg\AE\9E=\D6+n\EC\80\C8A\8C\AE\EB\CF\D5\DA\E9"2\A4\B9j5\EB\F3W\B63\96\B30Yu\DA\FC8\ED\DF\E7Ms\FB\F1\8E\B3\FA\EA\E8\E6(\883zs\F2_\8DFk\8Bh \00\8C\DCw\D3R\B5+6X\BA\B2\C4j\AB0\B4\FCMw\C2I\8E\9B\E3\A9~9u\FA\D3l\80\C8%p\EE\FDn2� \00$\FEj\C4e\A9\DB\~\95\A7\A5\80EK\BB\8DDsP\00@@AD'k\CF\E8\DB\D2(\80\9AK\D3\85\D6lb\F2\BA\8C*\80\00)\95 59\A3R:\F3\CE"\B6\80\88\00\00i1u4�\E9\F2�\A6\A2\FACM\93WMb*\E0*\00\00\00\00\00(\A8\80\00\00\80\00\00\00\00\00\00\00\00\00\FF\D9 C/// from compiler import ast # XXX should probably rename ASTVisitor to ASTWalker # XXX can it be made even more generic? class ASTVisitor: """Performs a depth-first walk of the AST The ASTVisitor will walk the AST, performing either a preorder or postorder traversal depending on which method is called. methods: preorder(tree, visitor) postorder(tree, visitor) tree: an instance of ast.Node visitor: an instance with visitXXX methods The ASTVisitor is responsible for walking over the tree in the correct order. For each node, it checks the visitor argument for a method named 'visitNodeType' where NodeType is the name of the node's class, e.g. Class. If the method exists, it is called with the node as its sole argument. The visitor method for a particular node type can control how child nodes are visited during a preorder walk. (It can't control the order during a postorder walk, because it is called _after_ the walk has occurred.) The ASTVisitor modifies the visitor argument by adding a visit method to the visitor; this method can be used to visit a child node of arbitrary type. """ VERBOSE = 0 def __init__(self): self.node = None self._cache = {} def default(self, node, *args): for child in node.getChildNodes(): self.dispatch(child, *args) def dispatch(self, node, *args): self.node = node klass = node.__class__ meth = self._cache.get(klass, None) if meth is None: className = klass.__name__ meth = getattr(self.visitor, 'visit' + className, self.default) self._cache[klass] = meth ## if self.VERBOSE > 0: ## className = klass.__name__ ## if self.VERBOSE == 1: ## if meth == 0: ## print "dispatch", className ## else: ## print "dispatch", className, (meth and meth.__name__ or '') return meth(node, *args) def preorder(self, tree, visitor, *args): """Do preorder walk of tree using visitor"